Carburetor for use with internal-combustion engines



C. AND G. WILLEBY.

CARBURETOR FOR USE WITH INTERNAL COMBUSTION ENGINES.

APPLICATION FILED NOV. 23, I921- Patented Oct 24, 1922, I 3 SHEETS-SHEET I- III? mezawm 6. 6. Mai/Zeb Fig.4.

0. AND 0. WILLEBY.

CARBURETOR FOR USE WITH INTERNAL COMBUSTION ENGINES.

APPLICATION FILED NOV-23,1921.- 1 433 5 Patented ($011.24, 1922.,

3 SHEETSSHEET 2.

C. AND G. WILLEBY.

CARBURETOF! FOR USE WITH INTERNAL COMBUSTION ENGINES.

APPLICATION FILED NOV- 23, I921.

Patehted 001:. 24, 11922..

3 SHEETSSHEET 3.

I; IIIIIIIIIIIII @6- (vii/26 Patented Oct 24, 1922.

Parent GFFHQEO CHARLES WILLEBY AND GUXWILLEBY, OF LEWES, ENGLAND;

Application filed November 23, 1921. Serial No. 517,377.

T all whom it may, concern:

Be it known that we, CHARLES WILLEBY and GUY WILLEBY, both subjects of the King of Great Britain and Ireland, and both re:

siding at Bowen, Laughton, Lewes, in the county of Sussex, England, have invented certain new and useful Improvements in and Relating to Carburetors for use with Internal-Combustion Engines, of which the following is a specification. I

This invention relates tomeans for th carburation of air by petrol or other liquid fuel for the working of internal combustion engines of the two or four-stroke cycle.

The primary object of the invention is to eifect the necessary carburation so that it shall be correct in its proportion of fuel to air at all engine speeds, thus ensuring the greatest power and economy under all con- 2 ditions.

This invention reduces the cost of manufacturing carburetors, and the likelihood of derangement and wear and tear. By means of the movementv of a choke tube, correct proportionate carburation and much greater economy of fuel are obtained. The control of the gases by means of the sleeve or the rotary throttle attached to the choke tube and worked by one and the same lever, or by the movement of the choke tube independently, is effected with much less reslstance to their passage than is possible by any form of throttle obstructing the main body of the carburetor, while at the same time a correct Venturi tube formation is preserved throughout.

The accompanying drawings illustrate embodiments of our improved carburetor.

In the drawings:

Figure 1 is an elevation partially in section of our improved carburetor wherein use is made of a movable cylindrical choke tube with co-acting sleeve valve;

Figure 2 is a sectional elevation of our improved carburetor wherein use is made of a movable cylindrical choke tube with 00- acting rotary valve;

Figure 3 is an elevation partially in section. of the structure shown in Figure 2 at 'les thereto;

ion of the structure shown in Figures 2 and a at right angles to Figure m the :w-n of the arrow;

Figure 5 is a plan thereof, and

Figure 6 is a sectional elevation of nozzle with frictional retarder;

In carrying the invention into effect a is a cylinder of tubular formation having a flared or trumpet-shaped mouth 6 forming the main air inlet. Located within the cylindera is a movable cylindrical choke tube 0 of varying internal diameter concentrically and slidably arranged about a submerged jet 03 positioned centrally within the cylinder or tube a, and having the lower end of the latter open longitudinally to admit the main air supply. In the disposition shown in F igure 1, there is attached to the choke tube 0, preferably by integral formation, an extension 'consisting of a tube or sleeve 7' which reciprocates with the choke tube 0 in such a manner as to form a throttle,

*hich by its rising or fallin action covers or uncovers an exit passage forming a conduit g, for the mixture, leading from the carburetor to the engine, and thus constitutes a combined throttle and choke tube action. The top end of thecylinder a is closed by a combined plug and cap it, the plug portion taking into the cylinder end to an extent which provides a space j between the plug and the top end of the sleeve valve f.

In the disposition shown in Figures 2 to 5, a rotary valve it having a shroud Z of segmental pattern is carried upon an axis 722. and co-acts with the cylinder a to constitute a combined throttle and choke tube action. The axis m is as shown, a two-part one consisting of gudgeon pins or trunnions and is supported in hearings in the members n and n forming walls of the upper portion of the cylinder (1, the member n acting as a cover removable at will and being of screw cap pattern.

In both dispositions of carburetor the combined throttle and choke tube action is effected through the agency of a pivoted lever 0, operable by foot pedal or otherwise, and connected to the upper end of a rod, bar. or link 7), which at its lower end is pivotally attached to the lower end of the choke" tube (2 by a stud or pin c slidable in a slot 1' provided in the cylinder 0 to allow for the reciprocable movement being imparted to the choke tube c.

Any suitable iorm oi nozzle may be used, but the nozzle (Z as shown in the drawing,

is of the submerged adjustable type, and is provided preferably with a device 8, (see Figure 6) centrally positioned in the nozzle tube zforming the central supply passage, and having a spiral groove around it externally to offer all friction possible for retarding the fuel flow at high speeds. The lower end of the nozzle tube t is connected to horizontal pipe t branching from a pipe '0 connected with petrol tank or chamber w, float regulated, see Figure 2.

The slow running or starting up device consists of a jet 00 positioned in a tubular chamber 11 attached to or forming part of the cylinder a. The fuel is drawn from the tank or chamber w and with air through the opening 2 is fed through the by-pass y, regulation of which is effected by the set screw 11/ Supplementary air admission openings (1 and 0 may be provided in the cylinder (1 and choke tube 0 if required.

In our improved carburetor as intended for aeroengines a further movement of the choke tube, after the throttle is fully opened, is allowed for, whereby the inherent richness that occurs with flying machines at high altitude is overcome.

We prefer the rotary throttle to the sleeve valve as working on bearings the throttle portion may be less suspectible to wear.

The throttle being placed at the top of the cylinder (z avoids obstruction to the passage of the mixture, which occurs with the ordinary type of barrel or butterfly throttle in which the mixture passes through it.

An important feature of the present invention is the straight through Venturi tube formation of the carburetor which is maintained throughout all engine speeds. and to that end the main air inlet is directly at the bottom instead of at the side as is usually adopted. A further important feature is that the choke tube has its small or narrow end downwards, and that the movement of the choke tube when the throttle is being opened, is longitudinally about the body of the nozzle and away from the induction passage.

Accordin to the dispositions shown in the drawings, *igures 1 to 5, air is admitted longitudinally to the cylinder at through the single inlet port at the lower end thereof through the choke tube 0 and past the fuel orifice; the choke tube 0 is at its highest position which is coincident with the throttle closed over the exist port. This is the position used for starting the engine or idling, petrol being then supplied solely through the by-pass by means of the auxiliary nozzle. The fuel is drawn through the auxiliary nozzle by suction created by the engine.

As the throttle is rotated the mixture in increasing quantity is admitted to the engine. At the same time and in proper ratio the choke tube 0 descends thus diminishing the suction on the nozzle orifice and supplying a mixture of petrol and air of correct proportions in relation to the trottle opening and consequent engine speed. The choke tube a, through its descent to the bottom of the cylinder-a or carburetor, is in a position to allow an unobstructed flow of combustible to the engine when such is required, viz, at

full throttle opening and high engine speeds.

Having now described our invention, what we claim as new and desire to secure by Letters Patent is In a carburetor, a tubular body, a fuel nozzle having an outlet arranged in said tubular body, an axially movable choke tube arranged concentric to the axis of said nozzle and having a venturi shaped inner surface, an air inlet provided at the lower end of said body and a mixture outlet opening arranged in the wall of the body near the upper end portion of the body, a laterally extending outlet pipe having its interior communicating with said outlet opening, the contracted portion of said venturi surface being arranged near the lower end of the choke tube, a axially movable throttle valve sleeve integral with said choke tube and controlling the mixture outlet, means for simultaneously actuating said sleeve and tube to cause the contracted portion of said veuturi surface to move away from the outlet of said nozzle and toward the air inlet while the throttle valve is opened, said contracted portion being arranged to occupy a position in close proximity to the nozzle outlet when the throttle valve is closed, and auxiliary air port arranged near the lower end of said body, and a port arranged in the choke tube and adapted to register with the other port when the throttle is fully opened for furnishing additional air to the tubular body.

In testimony whereof we have signed our names to this specification.

CHAS. IVILLEBY. GUY WILLEBY. 

